This is still such a weird promotion, though -- Apple has traditionally not had the best relationship with Facebook, but they have given away apps using Facebook before. Cupertino has a perfectly good Twitter account that could also be used to give away free games, but the Facebook freebies appear to use a slightly different method than posting promo codes. Don't forget Apple also has the Ping social network that could probably use a little traffic (and, you know, already happens to be connected up in iTunes).